Along‐arc heterogeneity in local seismicity across the lesser antilles subduction zone from a dense ocean‐bottom seismometer network

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Title: Along‐arc heterogeneity in local seismicity across the lesser antilles subduction zone from a dense ocean‐bottom seismometer network
Authors: Bie, L
Rietbrock, A
Hicks, S
Allen, R
Blundy, J
Clouard, V
Collier, J
Davidson, J
Garth, T
Goes, S
Harmon, N
Henstock, T
Van Hunen, J
Kendall, M
Kruger, F
Lynch, L
Macpherson, C
Robertson, R
Rychert, K
Tait, S
Wilkinson, J
Wilson, M
Item Type: Journal Article
Abstract: The Lesser Antilles arc is only one of two subduction zones where slow‐spreading Atlantic lithosphere is consumed. Slow‐spreading may result in the Atlantic lithosphere being more pervasively and heterogeneously hydrated than fast‐spreading Pacific lithosphere, thus affecting the flux of fluids into the deep mantle. Understanding the distribution of seismicity can help unravel the effect of fluids on geodynamic and seismogenic processes. However, a detailed view of local seismicity across the whole Lesser Antilles subduction zone is lacking. Using a temporary ocean‐bottom seismic network we invert for hypocenters and 1D velocity model. A systematic search yields a 27 km thick crust, reflecting average arc and back‐arc structures. We find abundant intraslab seismicity beneath Martinique and Dominica, which may relate to the subducted Marathon and/or Mercurius Fracture Zones. Pervasive seismicity in the cold mantle wedge corner and thrust seismicity deep on the subducting plate interface suggest an unusually wide megathrust seismogenic zone reaching ∼65km ∼ 65    km depth. Our results provide an excellent framework for future understanding of regional seismic hazard in eastern Caribbean and the volatile cycling beneath the Lesser Antilles arc.
Issue Date: 2020
Date of Acceptance: 26-Sep-2019
DOI: 10.1785/0220190147
ISSN: 0895-0695
Publisher: Seismological Society of America
Start Page: 237
End Page: 247
Journal / Book Title: Seismological Research Letters
Volume: 91
Issue: 1
Copyright Statement: © Seismological Society of America.
Sponsor/Funder: Natural Environment Research Council (NERC)
Funder's Grant Number: NE/K010743/1
Keywords: Science & Technology
Physical Sciences
Geochemistry & Geophysics
Geochemistry & Geophysics
0404 Geophysics
Publication Status: Published
Embargo Date: 2020-11-13
Online Publication Date: 2019-11-13
Appears in Collections:Faculty of Engineering
Earth Science and Engineering
Grantham Institute for Climate Change